This diploma paper deals with baby talk and its usage in the preschool institutions. In the theoretical part of this diploma paper the characteristics of pedagogical speech are examined in detail. Moreover, the difference between cognitive and relational speech is defined and a teacherʼs speech is presented in a variety of contexts. The main focus of this paper is on baby talk. Its characteristics as well as its research history and both the positive and negative influences of the baby talk-usage on a childʼs language development are explained. In the empirical part of this diploma paper the author determines which elements of baby talk are present in the teacher's speech to the children. For the research the author recorded the teacher's speech in 5 guided and 5 non-guided activities in a preschool institution. The results show that both the positive and negative elements of baby talk are present in the teacher's speech when she talks to the children. However, the frequency of the aforementioned elements varies according to the type of activity.